Tension controlling apparatus



2 Sheets-Sheet l o ma N e Mln @um TWOM N www m N N s G f www E A T www? lllhid T--- /mw G. E. HENNING ET AL TENSION CONTRQLING APPARATUS Filed 0G11. 7, 1942 Jan. 11, 1944.

Jan. 1,1, 1944. G. E.' HENNING ET A1. 2,338,848'

TENSION CONTROLING APPARATUS Filed Oct. '7,v 1942 2 Sheets-Sheet 2 l/VVENTES G E. HENNING O. G. NELSON J. A. WAGNER [5V/fw? l. A-f/f H77' ORNE Y Patented Jan. 11, 1944 l TENSION ooN'raoLLnfIG APPARATUS George E. Henning, Joppa, and Oscar G. Nelson and Julius A. Wagner, Baltimore, Md., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application October 7, 1942, Serial No. 461,180

Claims. (Cl. 5771) 'I'his invention relates to tension controlling apparatus and more particularly to an apparatus for controlling the tension of strands being wound on a take-up reel.

It is an object of the present invention to provide an automatic apparatus for accurately maintaining constant the tension in material being handled.-

In accordance with one embodiment of the invention, an apparatus is provided for controlling the tension in a pair of strands as they are taken up on the'take-up reel of a twisting machine. In the twisting machine, a flyer is provided for imparting a twist to the pair of strands and the take-up reel is mounted within the iiyer and concentric with its axis of rotation. I'I'he tension in the strands is maintained constant by providing a differential gear mechanism receiving power from the yer driving motor and also from an induction type torque motor and delivering the power to drive the take-up reel. Since, if the applied voltage is constant, the torque output of this type of motor varies at a known rate as the speed of the motor varies, this characteristic of the torque motor is utilized to maintain the tension constant as the winding diameter of the reel increases.

A clear 'understanding of the invention may be had by reference to the following detailed description, when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a side elevational view of a strand twisting machine, parts being broken away to .more clearly illustrate the details of constructially along the line 4-4 of Fig. 3 in the direction of the arrows, and

Fig. 5 is a diagram of a torque-speed curve oi a torque motor suitable for use in practicing the invention, showing the portion of the torquespeed curve which is utilized in maintaining constant tension in the strands being taken up in accordance with the present invention.

Referring to the drawings, it will be noted, by reference to Fig. l, that a pair of strands I0 and II are being fed into the apparatus and twisted by a yer I2, which then directs them to a takeup reel I3 driven by'an arrangement of'gears I4 and 'reciprocated by a distributor drive I5 to lay the twisted strands I0 and II evenly upon the reel I3. Power for driving the yer I2 is supplied by a main drive motor I6, which is directly coupled to the flyer and, through the arrangement of gears I4, to the take-up reel I3. The strands I0 and I I are drawn into the twister by a capstan Il mounted in the` ilyer and driven through a change gear mechanism I8 from the main drive motor I6.

The iiyer I2 comprises a balanced framework 22 provided with hollow trunnions 23 and 24,^.

which are freely rotatable in standards 25 and 26, respectively. .'Ihe strands I0 and II are fed through the trunnion 24 to the capstan Il, which is mounted on 'an end block 2l of the framework 22 and which is counterbalanced by a weight 23 mounted on the end block 21. Encircling the trunnion 24 is a sprocket 29, adapted to be driven about the trunnion 24 by a chain belt 30, which is, in turn, driven by the change gear mechanism I8 at a selected speed to drive the capstan at the desired rate. The sprocket 29 is secured to a gear 3l in mesh with an idler gear 32 freely rotatable on the end block 2l and transmitting driving motion from the gear 3| to a'pinion 33.' The pinion 33 is fixed to a vshaft 34, `carrying at its right end (Fig. 1) a small bevel `pinion 35, which meshes with a bevel gear 36, suitably fixed to the capstan I'I. In this manner, the capstan Il is driven at a rate directly proportional to the rate of speed of the driving motor I6. The mechanism for driving the capstan I1 is counterbalanced by the counterweight 2.8 and a' pair of ccunterweights 31 and 38, which are mounted -on the end block 21' of the yer I2 and which will compensate for the weight or the idler 32 and the pinion 33.

The trunnion 23 is provided with a sprocket 43 extending around its 'periphery and in mesh with a chain belt 44. The sprocket 43 is keyed to the trunnion 23 by a key member 69 and is "held against movement axially of the trunnion by spacers 68-68. The chain belt 44 is driven by the main drive motor i6 through the shaft 45 and gear 46, the shaft 45 extending over to and driving the change gear mechanism I8. Thus, the capstan Il and flyer I2 are positively geared one to another and driven by the main drive motor I6 at a constant rate of speed to draw the strands I0 and II into the flyer I2 to impart a deiinite amount of twist to each unit of length drawn into the flyer.

From the capstan I'I, the twisted strands I0 and II are directed over a pair of guideV rollers 4l and 48 angularly disposed with respect one to another and mounted on the balanced framework 22 of the iiyer for guiding the twisted strands to the take-up reel I3. The take-up reel I3 is removably xed to the lett end (Fig. 1) oi. a shaft 58 by means of a retainer 5I, which is adapted to hold the take-up reel I3 on the shaft 50. addition to the retainer member 5I, the shaft 50 has a disc 52 xedthereto and carrying a locking stud 53 in position to engage in an aperture 54- in reel I3 to lock the reel ron the shaft 50 for rotation with itl By reference to Figs. 3 and 4, it will be noted that theshaft 58 has a keyway 55 formed therein for receiving a spline 58 formed on a gear 16 described more fully hereinafter. The gear 16 is keyed to a' sleeve 51 by means of a key'56. This construction'permits the shaft 58 to be yreciprocated along its axis with respect to the sleeve 51 and at the same time to be rotated with the sleeve 51 which is journalled in the hollow trunnion 23. A

A reciprocable drivingrack 59 is attached to the right hand end of shaft 50, as seen in Fig. 1, in such manner that the shaft 5I) -is free y to rotate but may be reciprocated by the driving rack 59. The driving rack 59 meshes with a pinion 60 which may be rotated by the distributor drive .I5 to reciprocate the shaft 50. A pair of switches 6I and 62 are provided for reversing the current supply to the motor driving the distributor drive I5 under control of a switch actuating pin B3 attached to the underside of the rack 58.

Fixed to the trunnion `23, by means of a key 81. is a rotatable housing 10, having in its lower I end, as viewed in Fig. 1, a counterweight 1I for counterbalancing rthe housing 10. In the upper part of the housing 10, as viewed in Figs. l and 3, there is journalled a stud shaft, 12, which extends out through a housing cover plate 13 and carries a pair of gears 14 and 15 fixed thereto. The gear 14 meshes with a gear 18 upon which is formed integrally the spline 58. The gear 15 meshes with an idler gear 11 mounted upon a stud 18, which may be locked in various positions in an arcuate slot 19 (Fig. 4). The gear 15 may be replaced with various sized gears and the idler gear 11 maybe adjusted to compensate for the various sizes of the gear 15 which may be used in the gear train. The idler 11 is adjustable about the axis of the shaft 50, always being maintained in mesh with a sleeve gear 80, which is mounted for rotation on a sleeve 8| extending from and concentric with the cover plate 13, the sleeve gear 88 being locked in place on'the sleeve 8| by an annular collar 82 fixed to the sleeve 8|. The sleeve gear 88 has teeth 83 formed on its periphery for engagement by a chain belt 84, which` is driven by an induction type torque motor 86.

From the foregoing, it is believed t'o be apparent that the gears 83, 11, 15, 14 and 18 comprise a diiferential mechanism of the sun and planet type, whereby power from the main drive motor I3 and torque motor 86 Willkbe supplied difierentially to drive the take-up'ffieel I3 at a speed depending upon the speed the rotation of the flyer I2, vvlh is driven directly by the motor I6. and the speed of the motor 86. Since the rate of feed of the twisted strands I0 and II 1s constant, the take-up reel I3 must be vcaused to rotate at a gradually increasing speed from an empty reel to a full reel and the amount of torque applied to the reel I3 should also gradually increase as the reel lls up with the strands.

Becaue the torque ot an induction type torque motor decreases gradually from 100% torque to zero torque as its speed increases from of synchronous speed to of synchronous speed, providing the proper resistance is wound ln the secondary of the torque motor and the applied voltage is constant, this characteristic of this type of motor may be utilized to apply the proper tension to the strands being wound on the takeup reel. A torque motor should be chosen having such resistance in its secondary circuit that the torque-speed curve thereof will correspond substantially to the curve shown in Fig. 5. The

,various member of the apparatus are so designed that the portion of this curve falling between the vertical lines marked full reel and empty reel on Fig. 5 will be utilized. AsA a result, as the reel I3 fills up gradually, the proper torque to maintain the desired tension on the strands I0 and II will be applied to the reel until the reel is filled.

In the operation of the apparatus; the housing 10 which is driven with the ilyer I2 will tend to drive the shaft 50 (and the reel I3) through the gears 14 and 18 at the same speed as the ilyer if the gear 14 is prevented from rotating. However, the gear 14 is not prevented from rotating, but is driven by the torque motor 88in the direction indicated by the arrow thereon, which tends to retard therotation of the reel I3 so that the reel will rotate at a speed diierent from that of the flyer. With respect to the yer I2 the reel a rotates in a direction opposite to the direction of rotation of the ilyer,while with respect to the whole apparatus the reel rotates in the same direction as the flyer but at a slower speed. When the reel is empty and is rotating at its slowest speed, the' torque motor 86 must rotate at its highest speed and when the reel isA full and is rotating at its highest speed, the motor 86 ymust rotate at its lowest speed. A torque motor may be provided with such a resistance in its secondary circuit that it will have a substantially constant power output for a given range of speed, i. e., as its speed decreases, its torque will increase proportionately. Referring to the torque-speed curve of such a motor (Fig. 5), it will be seen that when the reel is empty, the -motor speed will be 'high and a low retarding torque will be applied to the reel and when the reel is full, tle motor speed will be proportionately lower and a higher retarding torque willbe applied to the reel. Thus, the speed of rotation of the reel I3 will approach the speed of rotation of the iiyer I2 as the reel lls up and the tension on the twisted strands being wound upon the reel I3 will be constant throughn out' the reeling operation.

When it is desirable to change the lay of the twist given to the strands III and II as they are twisted together by the flyer I2, the change gear mechanism I8 is adjusted accordingly to change the speed of rotation of the capstan I1. This will also change the linear speed at which the twisted wires are fed to the take-up reel I3. Con.-

sequently,nthe gear 15 must be replaced by another gear of suitable size to cause the reel I3 to rotate at the speed necessary to take up the twisted wires as fast as they are fed thereto. When the gear 15 is replaced,v the stud 18 is adjusted in the arcuate slot 19 so as to cause the gear 11 carried thereby to mesh with the gear that replaces the gear 15.

It will be seen that 1n this apparatus the tension control mechanism is mounted outside of rthe ilyer, thereby simplifying the problem of balancing the yer to avoid vibration when operating at high speeds. This construction also makes the control mechanism readily accessible for maintenance and permits the gear 15 to be readily replaced.

What is claimed is:

v 1. A tensioning apparatus comprising a rotatablexmember for engaging a supply f material to be tensioned, driving means voperable at a xed rate of speed, driving means operable at a variable'I rate of speed, and means operable jointly by said driving means for rotating said rotatable member to apply a. predetermined tension to said material. t

2. A tensioning apparatus comprising a .rotatable member.for engaging a supply of material to be tensioned, .a diiierential gear system for said member, driving means operable at a xed speed for driving said gear system, and a second driving means operable at variable speed `ior driving said gear system to apply-a predetermined tension to said material.

3. A Vtensioning apparatus comprising a ro'- tatable take-up member for strand material, a differential gear 'for actuating said member, said diiierential gear having two power inputs, a con,- stant speed -source of power connected to one of said power inputs, and a motor having a substantially .constant power at a variable speed connected to the other power input.

4. An apparatus for maintaining constant the to a take-up reel, comprising a constant speed drive for deliveringsaid strands, and means for driving the take-up reel .comprising a differential gear mechanism having two inputs and one oui:.l

put, means connecting said output to the takeup reel; means connecting one of said inputs .positively to the Idrive for delivering the strands, a Qtorque motor, and means connecting the torque motor positively to the other input of the diner- -ential gear mechanism'to increase the torque applied to-the take-up reel as its speed of rotation increases.

` 5. An apparatus for maintainingconstant thetension in strands being twisted by a iiyer and delivered to a take-up reel, comprising driving means for driving the reel concentrically with the l nyer, a diierential mechanism for :transmitting power to said driving means, a power source for applying power to the flyer and diilerential mechanism, and means for controlling the torque e output of the diiterential mechanism comprising a fixedA rate of speed, driving 'means operable at a variable rate of speed, and differential gear mechanism positively connected to both of said v driving means for rotating said rotatable member to apply a predetermined tension to said .materiaL r`tatable member for engaging a supply of4 ma- 8. A tensioning apparatus comprising a roterial to be tensioned, driving means operable at tensionv in strands being deliveredv at a xed'rate y a flxed rate of speed, a torque motor operable at a variable rate of speed, and means operable jointly by said driving means and said torque motor for rotating said rotatable member to apply a predetermined tension to said material. Y

9. A temsioning apparatus comprising a rotatable member for engaging a supply of material to be tensioned, driving. means operable at a xed rate of speed, a torque motor operable at a variable rate of speed, and gear mechanism operable jointly by said drivingl means and said torque motor for rotating said rotatable member to apply a predetermined Atension to said material. 1

' 10. A tensioning apparatus for controlling the take-up reel of a ilyer type strand twisting apparatus, comprising a shaft for supporting the reel coaxially of the flyer, a differential gear mechanism for driving said shaft having its output gear connected to said shaft, means for driv- `ing the ilyer and one of the input gears of the diierential gear mechanism, and a torque motor for driving the otheriinput gear of the differl ential gear mechanism.

GEORGE E. HENNING. OSCAR G. NELSON. JULIUS A. WAGNER. 

